There is a pressing clinical need for a non-invasive measure of body iron stores that is safe, accurate, and readily available. The only instrument that is clinically validated for non-invasive measurement is a magnetic susceptometer based on superconductivity, but its complexity, cost (approximately $1,000,000), and requirement for liquid helium have restricted its use to a handful of research centers. Since no simplification or cost reduction has occurred for over two decades, it has been widely assumed that superconductivity-based susceptometry is unlikely to enter general clinical practice. Using an integrated systems approach, the complexity/cost issue has recently been addressed in a BRP program supported by the NIDDK. This has resulted in a design that significantly simplifies both the instrument and the measurement procedure. It also reduces the system cost by over a factor of ten, while retaining the intrinsic accuracy of superconducting instrumentation. The new device still requires a cryogen (liquid nitrogen) that must be regularly replenished. The goal in Phase I of this SBIR is to exploit recent advances in cryocooler technology so as to remove this final barrier to clinical implementation. Simple low-cost cryosusceptometers would rapidly satisfy the pressing iron assessment need and open up many other applications for superconducting susceptometry, in both medicine and industry.